WWVB

Abstract

In commemoration of its 50th anniversary of broadcasting from Fort Collins, Colorado, this paper provides a history of the National Institute of Standards and Technology (NIST) radio station WWVB. The narrative describes the evolution of the station, from its origins as a source of standard frequency, to its current role as the source of time-of-day synchronization for many millions of radio controlled clocks.

Accurate, Traceable, and Verifiable Time Synchronization for World Financial Markets

“…The requirement was originally enforced only for the NASDAQ stock market, but the NYSE, through Rule 132A [15], adopted requirements identical to NASD Rule 6953 in 2003. Figure 1 shows an OATS compliant clock, still available at this writing, that can obtain NIST time from either radio station WWVB at 60 kHz [16] or from the NIST Internet Time Service (ITS) [17].…”

“…Because UTC(NIST) is a close real-time approximation of UTC, it can also be utilized as an official time source for financial exchanges throughout the world. NIST distributes UTC(NIST) to the general public through a variety of services that operate over various mediums including WWV, WWVH, and WWVB, which broadcast time signals via high frequency (HF) and low frequency (LF) radio signals [16,32]; by the Automated Computer Time Service (ACTS), which broadcasts time codes via ordinary telephone lines [33]; and by the Internet Time Service (ITS), which broadcasts billions (10 9 ) of time codes per day via the public Internet [17]. However, due to uncompensated propagation delays, each of these services delivers time to the user that is far less accurate than the time kept at NIST.…”

A Century of WWV

“…After several years of testing, the experimental station was issued the call sign WWVB. Exploration of very low frequency (VLF) standard frequency broadcasts was advanced in 1960, when another NBS station called WWVL broadcasting at 20 kHz began operation in a canyon near Boulder [30].…”

“…At about 80 km from the Boulder Laboratories, the site was considered far enough away to prevent the LF and VLF broadcasts from interfering with experiments there. However, it was considered near enough for the driving distance between the station and the laboratory to be reasonable, and for the station frequency to be easily controlled by the Boulder frequency standard [30].…”

“…This was the first use of a time code on a low-frequency broadcast. Although it initially had few users, it would later become the mostused feature of any of the time and frequency broadcasts [30].…”